Sizing textile fabric



Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE SIZING TEXTILE FABRIC No Drawing. Application September 9, 1936,

I Serial No. 99,951

9 Claims. (CI. 91-68) This invention relates to a method for sizing textile fabric and to the product thereof, and

more particularly relates to a method for sizing textile fabric by means of a thermoplastic filmforming compositionresistant to hydrolysis by alkaline washing solutions. The object of this invention is to produce permanently sized textile fabric suitable for articles of wearing apparel customarily starched, which after pressing with a hot iron, is transformed into a stiffer materialhaving an apparently heavier body and, generally, a starched' appearance.

A further object of this invention is to provide a sized textile fabric from which the sizing material is not removed by repeated laundering, which needs only ,to be pressed with a hot iron to produce a stiff, yet pliable, starch-like finish, and which is porous so as to allow the passage of water and moisture. A further object of this invention is to provide a pliable, yet firmly-set textile fabric in which tears and rips proceed with greater difficulty than in the untreated material, and in which adjacent threads are not strained or loosened when the material is torn.

The product in accordance with this invention comprises a textile fabric which contains a solid, thermoplastic, film-forming material which is substantially inert to the action of aqueous alkaline solutions throughout the individual threads thereof, and bonding adjacent threads together, but not forming a continuous coating on the individual threads or filling the interstices between the individual threads. This product will be found to be permanently sized and of a starched appearance which is retained after many washing and ironing operations, even when the washing is carried out in strong alkaline solutions.

The method in accordance with this invention comprises impregnating a textile fabric with an aqueous emulsion of a solution of a solid, thermoplastic, film-forming material substantially inert to the action of aqueous alkaline washing solutions in a volatile substantially water-immiscible solvent, removing the excess emulsion from the cloth, evaporating the water and the volatile solvent from the impregnated fabric and pressing at an elevated temperature, as with a hot iron, preferably at a temperature within the range of about 320 F. to about 360 F.

In following my method the excess emulsion may be conveniently removed from the cloth by passing the cloth between padded rolls. The

amount of emulsion remaining in the cloth after the excess has been removed, will desirably be such that the amount of dry thermoplastic composition remaining in the fabric at the end of my procedure will be sufficient to impregnate the individual threads of the fabric and to substantially bond the threads together where directly adjacent, but insufiicient to fill the interstices between the threads or to form a continuous coating over the surface of the textile. The amount of the dry thermoplastic composition remaining in the fabric will ordinarily be within the range of about 5% to about 40% by weight of the untreated cloth.

The aqueous emulsion used in accordance with my invention will comprise an emulsion of a solution of a solid thermoplastic, film-forming material substantially inert to the action of alkaline washing solutions in a suitable volatile. solvent therefor which is substantially immiscible with water. Thermoplastic materials which are suitable for use in accordance with this invention are organic esters of cellulose, as, cellulose acetate, cellulose propionate, etc.; mixed esters of cellulose, as, cellulose nitro acetate, cellulose aceto-butyrate, cellulose aceto-laurate, etc.; cellulose ethers, as, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, butyl cellulose, etc., poly vinyl acetate resins; mixed vinyl acetate-vinyl chloride resins; polyacrylic acid ester resins, as, poly ethyl acrylate, polymethyl acrylate, methyl methacrylate; mixtures of vinyl and acrylate resins, mixtures of glycol, glycerol and glycol esters of terpinene maleic anhydride resins, chlorinated rubber, rubber hydrochloride, chlorinated rubber hydrochloride, etc. Nitrocellulose is not suitable for this purpose, since it is not resistant to the action of aqueous alkaline solutions, and is not a true thermoplastic.

The solution of the thermoplastic material may, if desired, contain a suitablesoftening or plasticizing agent for lowering the softening temperature of the material. When using a material which softens at a temperature of 400 F. or above, a plasticizer will desirably be added. The plasticizer selected for this purpose will desirably be resistant to hydrolysis in alkaline solutions. The particular plasticizer used will also desirably be compatible with the thermoplastic material used. Suitable plasticizers for use with phosphate, tributyl phosphate, methyl phthallyl methyl glycollate, ethyl phthallyl ethyl gycollate, etc.

The aqueous emulsion which I use will contain an emulsifying agent or mixture of emulsifying agents and will desirably be finely dispersed. Suitable emulsifying agents are, for example, the alkali metal salts of the higher aliphatic half ester sulfates, as sodium lauryl sulfate, sodium stearyl sulfate, etc.; sulfonated oils, as sulfonated castor oil, sulfonated olive oil, etc.; soaps, as sodium stearate, sodium oleate, etc.; alkali metal salts of alkyl naphthalene sulfonic acids, as, sodium butyl naphthalene sulfonate, sodium isopropyl naphthalene sulfonate, etc.

The solids deposited in a textile fabric when impregnated with a thermoplastic film-forming material resistant to alkaline hydrolysis by the method in accordance with this invention, will generally be laid down in the threads of the fabric as an adherent mass. However, with certain impregnating materials, as for example, ethyl cellulose, an emulsion deposits the material as flufly, poorly adhering masses. In the use of such a material, it is desirable, although not essential, to subject the textile fabric to a pretreatment with a dilute aqueous solution of an inorganic salt, and preferably a salt of a polyvalent metal, prior to impregnating the fabric with the emulsion. Salts used for this purpose may be, for example, aluminum chloride, aluminum sulfate, zinc chloride, zinc sulfate, calcium chloride, etc. An aqueous solution of an inorganic salt having a concentration within the range of about 0.5% to about 3.0% by weight will be found suitable for this purpose.

The following examples further illustrate emulsion compositions suitable for the treatment of a textile fabric, such as for example, organdy, broad cloth, the heavy cotton fabric used for nurses uniforms, etc., in accordance with this invention.

Example I A solution of the following composition was prepared:

Per cent by weight Ethyl cellulos 16.6 Hydrogenated methyl abietate 3.4 Toluol 56.0 Butanol 16.0 Naphtha. (Hi-Flash) 8.0

Five hundred grams of the above solution was emulsified in 300 cc. of water containing 1.5 grams of sodium lauryl sulfate and 3 grams of sulfonated castor oil, to form an oil-in-water type emulsion by admixing the two solutions and passing the mixture through a colloid mill. The emulsion was uniform and of fine particle size.

Example II A solution of the following composition was prepared:

One hundred parts of the above formula are emulsified in 40 parts of water containing V 92, sodium lauryl sulfate and 1% sulfonated castor oil by admixture and then passage through a colloid mill.

Example II! Film phase:

Parts by weight Chlorinated rubber (Tornesit-30 cp.

grade) 100 Hydrogenated methyl abietate Oleic acid 4.9 Toluol 16 Xylol 110 Water phase:

Distilled water 98.5 NaOH 0.7

These two phases are run together through the The two phases may be shaken together for dispersion, or emulsified in a colloid mill.

The following examples further illustrate the method in accordance with this invention.

A sample of heavy, unsized cotton broadcloth was immersed in a 1% aqueous solution of aluminum chloride, passed between squeeze rolls and then immersed in an emulsion of the compositionshown in Example I, containing ethyl cellulose, The broadcloth saturated with the ethyl cellulose emulsion was then passed between padded squeeze rolls to remove the excess, and then through a drying tunnel at approximately 100 F. At this stage of the treatment the cloth was no stiffer than the untreated broadcloth, and microscopic examination showed that the individual threads of the cloth were impregnated with minute pellets of ethyl cellulose plastic. The treated broadcloth was pressed with a hot iron at a temperature ofyabout 340 F. After ironing, the weight of the broadcloth was found to have been increased about 30%. It was found to have a starched appearance, and to be much stiffer than the untreated cloth, yet still pliable. It was found to be more difficult to tear than the original cloth, and when torn gave a clean tear with unraveled edges. The interstices between the threads of the treated cloth were not closed, so that the treated cloth was not impervious to the passage of water and moisture, and can be used for the same purposes as the untreated broadcloth which has been starched. The broadcloth so treated has a decided advantage over broadcloth which has been starched, in that the sizing is not removed even after repeated launder- A sample of organdy was immersed in an emulsion of the composition shown in Example II, containing cellulose acetobutyrate. The organdy saturated with emulsion was then passed between padded squeeze rolls and through a drying tunnel. The cloth so treated was then pressed, with a hot iron at a temperature of about 340 F. The organdy so treated was found to have been increased in weight by about 25%, and to have a starched appearance.

It will be understood that the details and examples hereinbefore set forth are illustrative only, and that the invention as herein broadly described and claimed is in no way limited thereby.

What I claim and desire to protect by Letters Patent is:

1. A sized textile fabric characterized by stiffness and a starch-like finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about to about 40% of a composition comprising a solid thermoplastic material substantially resistant to the action of aqueous alkaline solutions and where said threads are directly out the interstices being filled by said thermoplastic composition.

3. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a plasticized thermoplastic composition comprising a thermoplastic cellulose derivative substantially resistant to the action of aqueous alkaline solutions and where said threads are directly adjacent, being bonded together by the thermoplastic composi tion, without the interstices being filled by said thermoplastic composition.

4. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a composition comprising cellulose acetobutyrate and where said threads are directly adjacent, being bonded to- Dlasticized chlorinated rubber.

5. A sized textile fabric characterized by stiflness and a starchlike finish in the absence of starch, by pliabilityand perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a composition comprising ethyl cellulose and where said threads are directly adjacent, being bonded together by the ethyl cellulose, without the interstices being filled by the ethyl cellulose.

6. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a composition comprising chlorinated rubber and where' said threads are directly adjacent, being bonded together by the chlorinated rubber, without the interstices being filled by the chlorinated rubber.

7. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a composition comprising plasticized cellulose acetobutyrate and Where said threads are directly adjacent, being bonded together by the plasticized cellulose acetobutyrate, without the interstices being filled by the plasticized cellulose acetobutyrate.

8. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a composition comprising plasticized ethyl cellulose and where said threads are directly adjacent, being bonded together by the plasticized ethyl cellulose, without the interstices being filled by the plasticized ethyl cellulose.

9. A sized textile fabric characterized by stiffness and a starchlike finish in the absence of starch, by pliability and perviousness to both moisture and air, and by having the individual threads thereof discontinuously impregnated with from about 5% to about 40% of a c0mposition comprising plasticized chlorinated rubber and Where said threads are directly adjacent, being bonded together by the plasticized chlorinated rubber, without the interstices being filled by the WYLY M. BILLING. 

